Nahla - black lab pup

So Nahla is an 8 month old black lab, pointer mix. She is a female, and normally a very happy friendly dog. Just recently my family and I started noticing a bit more of aggression and biting in her, mostly when attempting to put her in the cage for the night. She used to go in very good, quick cookie, she'd jump right in and fall asleep. Now, she'...